In a saucepan, combine the milk and orange liqueur and bring to a boil. Meanwhile, in a bowl, whisk together the egg, three yolks, and sugar until the mixture is pale. In a separate bowl, beat the butter until soft and creamy.

When the milk starts to boil, remove from heat and gradually pour it into the egg mixture, whisking constantly. Sift in the flour and add it to the saucepan, continuing to whisk until fully incorporated. Return the saucepan to the heat and cook, stirring constantly, until the pastry cream thickens. Once you reach the desired texture, transfer the cream to a bowl, add the ground almonds and the creamed butter, and whisk until you have a smooth almond cream.

Let the cream cool to room temperature. Cover with plastic wrap to prevent a skin from forming, and once cooled, refrigerate.

Preheat the oven to 400°F (200°C).

Place the puff pastry sheet on a baking tray. Brush the edges with a beaten egg yolk, fold the edges over about a finger’s width all around, and brush the folded edges again. Prick the center of the pastry with a fork to prevent it from puffing up. Bake for about 25 minutes, or until golden brown.

Let the puff pastry cool. Take the almond cream out of the fridge and spread it over the pastry. Smooth the top, then arrange the berries on top. I used red berries.